1H chemical shift assignments for cobrotoxin II

A Chain A, Nmr Solution Structure Of Cbt2

1H Assigned Chemical Shifts for Neurotoxin B (ntb)

The solution conformation of cobrotoxin has been determined by using proton
nuclear magnetic resonance spectroscopy. With the combination of various
two-dimensional NMR techniques, the 1H-NMR spectrum of cobrotoxin was
completely assigned (Yu et al., 1990). A set of 435 approximate interproton
distance restraints was derived from nuclear Overhauser enhancement (NOE)
measurements. These NOE constraints, in addition to the 29 dihedral angle
constraints (from coupling constant measurements) and 26 hydrogen bonding
restraints (from the pattern of short-range NOEs), form the basis of 3-D
structure determination by the hybrid distance geometry-dynamical simulated
annealing method. The 23 structures that were obtained satisfy the experimental
restraints, display small deviation from idealized covalent geometry, and
possess good nonbonded contacts. Analysis of converged structures indicated
that there are two antiparallel beta sheets (double and triple stranded), duly
confirming our earlier observations. These are well defined in terms of both
atomic root mean square (RMS) differences and backbone torsional angles. The
average backbone RMS deviation between the calculated structures and the mean
structure, for the beta-sheet regions, is 0.92 A. The mean solution structure
was compared with the X-ray crystal structure of erabutoxin b, the homologous
protein. This yielded information that both structures resemble each other
except at the exposed loop/surface regions, where the solution structure seems
to possess more flexibility.

Yu C, Bhaskaran R, Chuang LC, Yang CC.
Solution conformation of cobrotoxin: a nuclear magnetic resonance and hybrid distance
geometry-dynamical simulated annealing study.
Biochemistry. 1993 Mar 9;32(9):2131-6.

Solution conformation of cobrotoxin: a nuclear magnetic resonance and hybrid distance geometry-dynamical simulated annealing study.

Cobrotoxin II (CBT II) (CBT2) (Short neurotoxin 5) (Short neurotoxin 1)